add document, fix tooltip position issue

css/functions/checkbox.scss

@@ -8,7 +8,6 @@ $boxDisabledColor: #d9d9d9;
     .check-box-inner {
         position: relative;
         display: inline-block;
-        margin-top: 2px;
         padding: 0;
         width: 14px;
         height: 14px;